The situation presented, in which an outer part of the body has to be connected to an inner part by hemming, arises for example in the case of wheel arches of vehicle bodies. The outer shell of the body has a circular arced, preferably semi-circular section, on the rim of which the so-called wheel arch is fastened on the inner side of the body. The problem here is that the outer side of the outer shell should not be deformed or at least deformed as little as possible, i.e. must not for example receive any dents or scratches, since these would be immediately visible when the outer shell is subsequently painted, and would spoil the aesthetic effect which the vehicle body is intended to impart.
In principle, this therefore prohibits using hemming device comprising pressing and counter pressure rollers, since the counter pressure roller would then run along the outer side of the outer shell and could deform it. The solutions known hitherto get by using sliders which are moved radially outwards behind the rim of the outer shell, with respect to the wheel section, and thus turn it inwards. Since a counter pressure is omitted here, the quality of the hem is not always satisfactory. Moreover, this is relatively involved equipment which only caters specifically for the body of one type of vehicle in each case, which makes using it in production facilities in which different types of body are built problematic.